Collapsible dispensing tube for non-solid materials

ABSTRACT

A collapsible dispensing tube includes an internal tube element made of a non-resilient flexible material and having a squeeze spout from which contents in the internal tube element is dispensed; an external tube element which accommodates the internal tube element to form an air chamber between the internal tube element and the external tube element, the external tube element being made of a resilient material having a hardness greater than that of the non-resilient flexible material of the internal tube element; and a small opening formed on the external tube element to be closable by one of a fingertip and a palm, the air chamber being communicatively connected to the outside of the external tube element via the small opening.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a collapsible dispensing tube from which a non-solid material is dispensed by squeezing the tube.

[0003] 2. Description of the Related Art

[0004] Collapsible dispensing tubes, or squeezable dispensing tubes, which serve as a non-solid material container, and from which the non-solid material (flowable material) is dispensed by squeezing the tube as needed, have been widely used in various fields. The non-solid material constituting the contents of the collapsible dispensing tube can be, e.g., medical paste, non-medical paste such as toothpaste, a cosmetic such as emulsion, or an eatable paste such as ketchup or tomato sauce.

[0005] Typical conventional collapsible dispensing tubes can be roughly divided into two types: a non-resilient type and a resilient type. The non-resilient type collapsible dispensing tube is made of, e.g., a soft metal or a single or multi-layered soft synthetic resin film, so that the collapsible dispensing tube remains deformed after squeezed to dispense the contents therefrom even if released from an external pressure applied to the collapsible dispensing tube. Due to this characteristic, air does not come into the tube. Accordingly, the contents of the tube do not easily change in quality, and is not easily contaminated by bacteria. Nevertheless, the outward appearance of the tube is not good.

[0006] On the other hand, the resilient type collapsible dispensing tube is made of, e.g. a single or multi-layered hard and resilient synthetic resin film, so that the collapsible dispensing tube returns nearly to its original shape upon a release from an external pressure applied to the tube after squeezed to dispense the contents from the tube, regardless of the remaining quantity of the contents. This feature does not disfigure the outward appearance of the tube, however, escaped air is always allowed to reenter into the tube (inflatable). This air oxidizes the contents of the tube to thereby change the quality of the contents of the tube, and accordingly becomes a leading cause of bacterial contamination of the contents of the tube. To prevent such problems from occurring, it is possible to put the cap (closure) back on the squeeze spout of the tube with the tube remaining squeezed to prevent air from coming into the tube, especially when the remaining quantity of the contents of the tube becomes small. However, even if the cap is put back on the squeeze spout in such a manner, air cannot be entirely prevented from entering the tube; furthermore, the ease of use of the collapsible dispensing tube is not good.

[0007] To overcome such problems, a collapsible dispensing tube having a flexible and resilient external tube element and a flexible but non-resilient internal tube element provided inside the external tube element has been proposed in, e.g., Japanese Unexamined Patent Publication No.2000-106262, wherein a squeeze spout of the internal tube element projects outwards from the external tube element in an air-tight fashion and wherein the external tube element is provided with a one-way valve (check valve) so that the contents of the internal tube element is dispensed from the squeeze spout thereof by squeezing the external tube element. According to this type of collapsible dispensing tube, the external tube element can be reused. However, it is difficult to use up the contents of the collapsible dispensing tube. In addition, even if the one-way valve is of a simple type, it is costly to provide the collapsible dispensing tube with such a one-way valve since it has to be prepared and fixed in position. This is particularly true when mass-producing the collapsible dispensing tube.

[0008] Moreover, in such a type of collapsible dispensing tube using a one-way valve, the more efficient the one-way valve operates, the greater the internal pressure relative to the outside pressure becomes due to a variation of the outside air-temperature or atmospheric temperature. Consequently, the possibility of the contents of the collapsible dispensing tube blowing out therefrom unexpectedly increases. If this happens, the reliability of the collapsible dispensing tube is instantly lost.

SUMMARY OF THE INVENTION

[0009] The present invention provides a collapsible dispensing tube wherein no air enters inside the tube even if the remaining quantity of the contents of the tube is small, and wherein at least the external part of the tube restores substantially to its original shape after squeezed to maintain a desirable outward appearance of the tube. The present invention further provides a low-cost disposable collapsible dispensing tube without using a conventional one-way valve.

[0010] For example, a collapsible dispensing tube is provided, including an internal tube element made of a non-resilient flexible material and having a squeeze spout from which contents in the internal tube element is dispensed; an external tube element which accommodates the internal tube element to form an air chamber between the internal tube element and the external tube element, the external tube element being made of a resilient material having a hardness greater than that of the non-resilient flexible material of the internal tube element; and a small opening formed on the external tube element to be closable by one of a fingertip and a palm, the air chamber being communicatively connected to the outside of the external tube element via the small opening.

[0011] In this double-layered collapsible dispensing tube, the internal pressure of the air chamber increases if an external pressure is applied to the external tube element with the small opening being closed by a fingertip or a palm of the user. This increase of the internal pressure of the air chamber applies a pressure to the internal tube element to dispense the contents from the squeeze spout. Accordingly, the contents in the internal tube element are dispensed from the squeeze spout by squeezing the external tube element. Immediately after the external tube element is released from an external pressure applied thereto after the use of the collapsible dispensing tube, air comes into the air chamber via the small opening, which causes the resilient external tube member to return to its original shape, whereas the internal tube member that has no resiliency remains deformed in accordance with the remaining quantity of the contents. Accordingly, no air enters inside the internal tube member, which reduces the possibility of the contents of the collapsible dispensing tube changing in quality and also the possibility of the contents of the collapsible dispensing tube being contaminated by bacteria.

[0012] An advantage of the collapsible dispensing tube according to the present invention is that a combination of the small opening of the external tube member and a fingertip or a palm of the user serves as a one-way valve (check valve). Since an area on the external tube element where the user is likely to touch when he or she uses the collapsible dispensing tube is almost fixed, it is desirable that the small opening be formed on that -e specific area. Since the air chamber is normally connected to the outside of the collapsible dispensing tube via the small opening, the internal pressure of the air chamber between the internal and external tube elements does not increase relative to the outside pressure due to a variation of the outside air-temperature or atmospheric temperature. Accordingly, the contents of the collapsible dispensing tube cannot blow out (explode) therefrom unexpectedly.

[0013] It is desirable that the internal tube element and the external tube element being each elongated and connected to each other at one end opposite from the squeeze spout.. This structure is advantageous for the collapsible dispensing tube to be squeezed to dispense the contents therefrom.

[0014] In order to make it easy for the collapsible dispensing tube to be squeezed, it is desirable that the other end of the external tube element, at which the squeeze spout is formed, has a round shape or an oval shape, and wherein the one end of the external tube element is formed as a flat end, the one and the other ends of the external tube element being connected smoothly via a major portion of the external tube element. Namely, it is desirable that the internal tube element be connected to the external tube element so that the internal tube element be squeezed together with the external tube element at the same time when the external tube element is squeezed in a direction from the other end to the one end of the external tube element.

[0015] It is desirable for the internal tube element to be connected to the external tube element in a manner so as to be squeezed together with the external tube element at the same time when the external tube element is squeezed in a direction from the one end to the other end of the external tube element.

[0016] It is desirable that the resilient material of the external tube element be translucent or transparent so that the remaining quantity of the contents in the internal tube element can be visually checked from the outside of the collapsible dispensing tube.

[0017] It is desirable for the squeeze spout to project outwards from said external tube element in an airtight fashion.

[0018] According to another embodiment, a collapsible dispensing tube is provided, including an internal tube element having a squeeze spout from which contents in the internal tube element is dispensed, the internal tube element remaining deformed after squeezed to dispense the contents therefrom even when released from an external pressure applied to the internal tube element; an external tube element which accommodates the internal tube element to form an air chamber between the internal tube element and the external tube element, the external tube element returning substantially to an original shape thereof upon a release from an external pressure applied to the external tube element after being squeezed to dispense the contents from the squeeze spout regardless of the remaining quantity of the contents; and a small opening formed on the external tube element to be closable by one of a fingertip and a palm, the air chamber being connected to the outside of the external tube element via the small opening.

[0019] The present disclosure relates to subject matter contained in Japanese Patent Application No.2001-186669 (filed on Jun. 20, 2001) which is expressly incorporated herein by reference in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be described below in detail with reference to the accompanying drawings in which:

[0021]FIG. 1 is a perspective view of an embodiment of a collapsible dispensing tube according to the present invention;

[0022]FIG. 2 is a cross sectional view taken along II-II line shown in FIG. 1;

[0023]FIG. 3 is a cross sectional view taken along III-III line shown in FIG. 2;

[0024]FIG. 4A is a cross sectional view of the collapsible dispensing tube shown in FIG. 1, showing a large remaining quantity of the contents of the collapsible dispensing tube;

[0025]FIG. 4B is a view similar to that of FIG. 4A, and illustrates the collapsible dispensing tube in a squeezed state to squeeze the contents thereof out of the tube; and

[0026]FIG. 4C is a view similar to that of FIG. 4A, and illustrates the collapsible dispensing tube in a free state after being squeezed in a way shown in FIG. 4B, showing a state where the remaining quantity of the contents of the collapsible dispensing tube is small.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0027]FIGS. 1 through 3 show the first embodiment of a collapsible dispensing tube 10 according to the prevent invention. The collapsible dispensing tube 10 is provided with an internal tube element 20 and an external tube element 30 which accommodates the internal tube element 20. The internal tube element 20 is flexible but not resilient, and thus remains deformed after squeezed even if released from an external pressure applied to the internal tube element 20, whereas the external tube element 30 is flexible and also resilient, thus returning nearly to its original shape upon removal of pressure. The internal tube element 20 is made of a relatively soft non-resilient flexible material such as a single or multi-layered synthetic resin film. A squeeze spout 21 is fixed to one end of the internal tube element 20. The squeeze spout 21 has a sufficient strength so that a cap 22 can be taken off and put back on the squeeze spout 21. The internal tube element 20 (at least the inner surface thereof) is made of a material which is chemically inert to the contents of the collapsible dispensing tube 10 accommodated in the internal tube element 20. When squeezed to dispense the contents therefrom, the internal tube element 20 does not suck air from the outside upon a release from an external pressure applied to the internal tube element 20since the internal tube element 20 has no resiliency. This type of tube material having no resiliency is well-known in the art.

[0028] The external tube element 30 accommodates the internal tube element 20 with an air chamber 40 being formed therebetween. The external tube element 30 is made of a flexible and resilient material having a hardness greater than the hardness of the material of the internal tube element 20, e.g., a single or multi-layered hard and resilient synthetic resin film. Accordingly, the external tube element 30 returns substantially to its original shape upon removal of pressure because of the resiliency thereof. This type of resilient tube material is well-known in the art.

[0029] The external tube element 30 is provided on opposite sides thereof with a round or oval spout-side end 32 and a flat end 33, respectively, and these two opposite ends 32 and 33 are connected smoothly via a major portion of the external tube element 30. The spout-side end 32 is provided with a round hole 34 from which the squeeze spout 21 projects outwards. The inner edge of the spout-side end 32 in the round hole 34 is fixed (bonded or welded) to the neck of the spout-side end 32 in an air-tight fashion. The inner tube element 20 is provided, at the end thereof opposite from the squeeze spout 21, with an extendable folding portion 23. The rear end (the right end as viewed in FIGS. 2 and 3) of the extendable folding portion 23 is fixed (bonded or welded) to the flat end 33 of the external tube element 30 in an air-tight fashion. The extendable folding portion 23 can be designed to form a chamber therein for accommodating some of the contents of the collapsible dispensing tube 10, or can be designed not to have such a chamber.

[0030] The external tube element 30 is provided with a small opening 31 having a small diameter which is closed by the fingertip or the palm of the user the collapsible dispensing tube 10 is squeezed. The small opening 31 is formed in an area on the external tube element 30 where the user is likely to touch when the collapsible dispensing tube 10 is in use. The air chamber 40 is communicatively connected to the outside via the small opening 31. The small opening 31 serves as an air-intake opening.

[0031] The internal tube element 20 and the external tube element 30 are coupled (assembled) to each other in the following described manner. In a state where the rear end of the external tube element 30 is open, the internal tube element 20 is inserted into the external tube element 30 from the rear open end thereof so that the squeeze spout 21 fully projects outwards from the round hole 34 of the spout-side end 32. Subsequently, the inner edge of the spout-side end 32 in the round hole 34 is fixed (bonded or welded) to a neck portion of the squeeze spout 21. Thereafter, the respective rear ends of the internal tube element 20 and the external tube element 30 are fixed (bonded or welded) to each other at the flat end 33. The internal tube element 20 can be filled with the contents of the collapsible dispensing tube 10 either before or after the respective rear ends of the internal tube element 20 and the external tube element 30 are fixed to each other at the flat end 33. This operation coupling the internal tube element 20 to the external tube element 30 is only an example, so that the internal tube element 20 and the external tube element 30 can be coupled to each other in any other appropriate manner.

[0032] In the present embodiment of the collapsible dispensing tube 10, the internal tube element 20 is filled with a non-solid substance and the cap 22 is tightly screwed on the squeeze spout 21 before shipment (see FIG. 2). As known in the art, depending on properties of the contents, the tip of the squeeze spout 21 is closed by a film member or a seal (not shown) which is adhered to the tip of the squeeze spout 21 before the cap 22 is screwed on the squeeze spout 21. This structure is basically the same as conventional structures of various ubiquitous collapsible dispensing tubes, and thus is familiar to the user.

[0033] When the collapsible dispensing tube 10 is used to dispense the contents therefrom, the external tube element 30 is squeezed with the small opening 31 being closed by a fingertip or a palm of the user after the cap (and also the seal if provided) is taken off the squeeze spout 21. As a result of the external tube element 30 being squeezed, the internal pressure of the air chamber 40 increases to thereby apply a pressure higher than atmospheric pressure to the internal tube element 20. Consequently, the internal tube element 20 is deformed and squeezed to dispense the contents from the squeeze spout 21.

[0034] Once the external tube element 30 is released from an external pressure applied thereto, air enters inside the air chamber 40 via the small opening 31, which causes the resilient external tube member 30 to return to its original shape, whereas the internal tube member 20, which has no resiliency, remains deformed in accordance with the remaining quantity of the contents (see FIGS. 4A and 4C). Accordingly, no air enters inside the internal tube member 20. This prevents the contents of the collapsible dispensing tube 10 from being changed in quality and contaminated by bacteria. The extendable folding portion 23 extends as the volume of the air chamber 40 increases as the contents of the internal tube member 20 decreases. The extendable folding portion 23 can be omitted depending on the shapes of the internal tube member 20 and the external tube member 30. A shoulder portion 20 a of the internal tube member 20 adjacent to the squeeze spout 21 is formed as a sloping, round shoulder portion having a smooth curved surface. The shape of the shoulder portion 20 a is advantageous for dispersing the contents of the collapsible dispensing tube 10 as much as possible.

[0035] The contents of the collapsible dispensing tube 10 can be squeezed out therefrom by squeezing the collapsible dispensing tube 10 in a direction from the flat end 33 to the spout-side end 32, especially when the remaining quantity of the contents of the collapsible dispensing tube 10 is small. FIG. 4B shows a state where the collapsible dispensing tube 10 is being squeezed to squeeze the contents therefrom in a direction from the flat end 33 to the spout-side end 32. The small opening 31 does not always need to be closed each time the collapsible dispensing tube 10 is squeezed. Namely, the collapsible dispensing tube 10 can be advantageously used in the same way as the way of a conventional collapsible dispensing tube.

[0036] The external tube element 30 is desirably made of a translucent or transparent material so that the remaining quantity of the contents in the internal tube element 20 can be visually checked. In this case, the remaining quantity of the contents in the internal tube element 20 can be visually checked by seeing the size of the internal tube element 20 through the transparent or translucent external tube element 30. The internal tube element 20 can also be made of a translucent or transparent material.

[0037] As can be understood from the foregoing, according to the present invention, no air comes into the collapsible dispensing tube even if the remaining quantity of the contents of the tube is small; moreover, at least the external part of the tube restores substantially to its original shape after being squeezed, so that the outward appearance of the tube is maintained. Furthermore, the internal pressure of the air chamber between the internal and external tube elements does not increase relative to the outside pressure due to a variation of outside air-temperature or atmospheric temperature. Therefore the contents of the collapsible dispensing tube never blows out therefrom unexpectedly since the air chamber is always communicatively connected to the outside via the small opening.

[0038] Obvious changes may be made in the specific embodiment of the present invention described herein, such modifications being within the spirit and scope of the invention claimed. It is indicated that all matter contained herein is illustrative and does not limit the scope of the present invention. 

What is claimed is:
 1. A collapsible dispensing tube comprising: an internal tube element made of a non-resilient flexible material and having a squeeze spout from which contents in said internal tube element is dispensed; an external tube element which accommodates said internal tube element to form an air chamber between said internal tube element and said external tube element, said external tube element being made of a resilient material having a hardness greater than that of said non-resilient flexible material of said internal tube element; and a small opening formed on said external tube element to be closable by one of a fingertip and a palm, said air chamber being communicatively connected to the outside of said external tube element via said small opening.
 2. The collapsible dispensing tube according to claim 1, wherein said internal tube element and said external tube element are each elongated and connected to each other at one end opposite from said squeeze spout.
 3. The collapsible dispensing tube according to claim 2, wherein the other end of said external tube element, at which said squeeze spout is formed, comprises one of a round shape and an oval shape, and wherein said one end of said external tube element is formed as a flat end, said one and the other ends of said external tube element being connected smoothly via a major portion of said external tube element.
 4. The collapsible dispensing tube according to claim 3, wherein said internal tube element is connected to said external tube element in a manner so as to be squeezed together with said external tube element at the same time when said external tube element is squeezed in a direction from said one end to said other end of said external tube element.
 5. The collapsible dispensing tube according to claim 1, wherein said resilient material of said external tube element is translucent.
 6. The collapsible dispensing tube according to claim 1, wherein said resilient material of said external tube element is transparent.
 7. The collapsible dispensing tube according to claim 1, wherein said squeeze spout projects outwards from said external tube element in an airtight fashion.
 8. A collapsible dispensing tube comprising: an internal tube element having a squeeze spout from which contents in said internal tube element is dispensed, said internal tube element remaining deformed after squeezed to dispense said contents therefrom even when released from an external pressure applied to said internal tube element; an external tube element which accommodates said internal tube element to form an air chamber between said internal tube element and said external tube element, said external tube element returning substantially to an original shape thereof upon a release from an external pressure applied to said external tube element after being squeezed to dispense said contents from said squeeze spout regardless of the remaining quantity of said contents; and a small opening formed on said external tube element to be closable by one of a fingertip and a palm, said air chamber being connected to the outside of said external tube element via said small opening. 